Antihypertensive DrugsAntihypertensive Drugs

Mechanisms Regulating Blood Mechanisms Regulating Blood PressurePressure

NeuralNeural HormonalHormonal VascularVascular Vascular RemodelingVascular Remodeling

NeuralNeural

Triggered by hypotension & Triggered by hypotension & inadequate tissue perfusioninadequate tissue perfusion

Release of epinephrine & Release of epinephrine & norepinephrine causingnorepinephrine causing• Constriction of blood vessels in the skin, Constriction of blood vessels in the skin,

kidney, & GIkidney, & GI• The heart rate and the force of the The heart rate and the force of the

contraction contraction

HormonalHormonalRenin-Angiotensin-Aldosterone Renin-Angiotensin-Aldosterone

System & VasopressinSystem & Vasopressin Renin is released in response to Renin is released in response to

• ________________• ________________• ________________

Renin converts angiotensinogen to Renin converts angiotensinogen to angiotensin Iangiotensin I

Angiontensin-converting enzyme Angiontensin-converting enzyme (ACE) produces angiontensin II(ACE) produces angiontensin II

Renin-Angiotensin-AldosteroneRenin-Angiotensin-Aldosterone

Renin-Angiotensin-Renin-Angiotensin-AldosteroneAldosterone

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Angiontensin IIAngiontensin II

Strongly constricts arteriolesStrongly constricts arterioles Increases/Decreases? peripheral Increases/Decreases? peripheral

vascular resistancevascular resistance Increases BP by direct Increases BP by direct

vasoconstriction, stimulation of the vasoconstriction, stimulation of the SNS, and stimulation of SNS, and stimulation of catecholamine releasecatecholamine release

Stimulates secretion of AldosteroneStimulates secretion of Aldosterone

AldosteroneAldosterone

Kidneys retain sodium and H2OKidneys retain sodium and H2O Retention of sodium and water Retention of sodium and water

increases ()increases ()• ______ ___________ _____• ______ ___________ _____• ______ ___________ _____

VasopressinVasopressinAntidiuretic Hormone (ADH)Antidiuretic Hormone (ADH)

Regulates _______ reabsorption by Regulates _______ reabsorption by the kidneysthe kidneys

Released in response to decreased Released in response to decreased blood volume and blood pressureblood volume and blood pressure

CausesCauses• Retention of fluidsRetention of fluids• vasoconstrctionvasoconstrction

VascularVascular

Endothelium damageEndothelium damage Production of vasoconstrictorProduction of vasoconstrictor Inability to respond to vasodialatorsInability to respond to vasodialators

Primary HypertensionPrimary Hypertension

Unknown etiologyUnknown etiology One or more of the compensatory One or more of the compensatory

mechanisms has gone awrymechanisms has gone awry

HypertensionHypertension

Definition pg 353Definition pg 353

Target OrgansTarget Organs

Antihypertensive DrugsAntihypertensive DrugsPrimary HypertensionPrimary Hypertension

Angitensinconverting enzyme (ACE) Angitensinconverting enzyme (ACE) Inhibitors (yes)Inhibitors (yes)

Angitensin II Receptor Antagonists Angitensin II Receptor Antagonists (no)(no)

Antiandrenergics (yes)Antiandrenergics (yes) Calcium Channel Blockers (yes)Calcium Channel Blockers (yes) Diuretics (yes)Diuretics (yes)

Angiotensin-Converting Enzyme Angiotensin-Converting Enzyme Inhibitors (ACE Inhibitors)Inhibitors (ACE Inhibitors)

Block the enzyme that converts Block the enzyme that converts angiotensin I to angiontensin IIangiotensin I to angiontensin II

Decrease vasoconstrictionDecrease vasoconstriction Decrease aldosterone productionDecrease aldosterone production Prevent or reverse remodeling of Prevent or reverse remodeling of

heart and vesselsheart and vessels

ACE InhibitorsACE Inhibitors

Caucasians-May be effective aloneCaucasians-May be effective alone African-Americans maybe used in African-Americans maybe used in

combination with diureticcombination with diuretic

ACE Inhibitor PrototypeACE Inhibitor PrototypeCaptopril (Capoten)Captopril (Capoten)

Choice for diabetic Choice for diabetic nephropathynephropathy

Renal protectiveRenal protective DOC for clients DOC for clients

with CHFwith CHF• 23-4 p. 36323-4 p. 363

Side EffectsSide Effects

10-20 % 10-20 % experience experience persistent coughpersistent cough

HypotensionHypotension HyperkalemiaHyperkalemia Renal failureRenal failure Sexual dysfunctionSexual dysfunction

ContraindicationsContraindications

PregnancyPregnancy

Nursing AssessmentNursing Assessment

Check BP Check BP accurately and accurately and repeatedlyrepeatedly

Monitor renal Monitor renal function function

HyperkalemiaHyperkalemia JaundiceJaundice

TeachingTeaching

Give one hour acGive one hour ac Continue to take Continue to take

even if feeling welleven if feeling well Antacids 2 hours Antacids 2 hours

before or after before or after

Beta BlockersBeta Blockers269, Lilley269, Lilley

DecreaseDecrease Heart rateHeart rate Force of myocardial contractionForce of myocardial contraction Cardiac outputCardiac output OO2 2 Demand by the heartDemand by the heart Renin release from the kidneyRenin release from the kidney Stimulation from SNSStimulation from SNS

Beta BlockerBeta Blocker

Drug of first choiceDrug of first choice <50 with high renin hypertension<50 with high renin hypertension TachycardiaTachycardia AnginaAngina MIMI Left ventricular hypertrophyLeft ventricular hypertrophy

Beta BlockerBeta Blocker

Greater effect on AsiansGreater effect on Asians African-American part of multi-drug African-American part of multi-drug

regimenregimen

Beta Blocker PrototypeBeta Blocker PrototypeLopressorLopressor

Available PO & IVAvailable PO & IV Available in Available in

extended releaseextended release Cardio selective Cardio selective

beta blockerbeta blocker

Side EffectsSide Effects

Fatigue Fatigue BradycardiaBradycardia CHFCHF Pulmonary EdemaPulmonary Edema ImpotenceImpotence

Nursing AssessmentNursing Assessment

Monitor BP, ECG, Monitor BP, ECG, PulsePulse

I & O & daily I & O & daily weightsweights

BUNBUN Liver functionLiver function

TeachingTeaching

Pulse & BP at homePulse & BP at home May cause May cause

drowsinessdrowsiness Drug must be Drug must be

taperedtapered ImpotenceImpotence Weight gain Weight gain

>2lb/wk>2lb/wk

Use CarefullyUse Carefully

Hepatic ImpairmentHepatic Impairment Renal ImpairmentRenal Impairment

Calcium Channel BlockersCalcium Channel Blockers

Used for several CV disordersUsed for several CV disorders In hypertensionIn hypertension

• Dilate peripheral arteries Dilate peripheral arteries • Decrease vascular resistanceDecrease vascular resistance

Choice for clients with anginaChoice for clients with angina Can use for renal impairmentCan use for renal impairment Use with caution with hepatic Use with caution with hepatic

impairmentimpairment

Calcium Channel Blockers Calcium Channel Blockers Prototype: Diltiazem Prototype: Diltiazem

(Cardizem SR)(Cardizem SR) Prevent movement Prevent movement

of extracellular Ca of extracellular Ca into the cellinto the cell

SR?SR? Slows the AV nodeSlows the AV node Decreases Decreases

systemic vascular systemic vascular pressurepressure

ContraindicationsContraindications

22ndnd and 3 and 3rdrd degree heart block degree heart block Cardiogenic shockCardiogenic shock Congestive heart failureCongestive heart failure Severe bradycardiaSevere bradycardia HypotensionHypotension

Side effectsSide effectsDiltiazem (Cardizem SR)Diltiazem (Cardizem SR)

Peripheral edemaPeripheral edema Arrhythmias Arrhythmias CHFCHF Stevens Johnson SyndromeStevens Johnson Syndrome

TeachingTeaching

Do not crush, Do not crush, break, or chewbreak, or chew

With or without With or without mealsmeals

May cause May cause drowsinessdrowsiness

PhotosensitivityPhotosensitivity

Nursing Implications Nursing Implications All AntihypertensivesAll Antihypertensives

TherapeuticTherapeutic Goal of tx is usually 140/90Goal of tx is usually 140/90

Adverse EffectsAdverse Effects Monitor postural hypotensionMonitor postural hypotension I & OI & O BradycardiaBradycardia Antiacids, andrenergics, & NSAIDSAntiacids, andrenergics, & NSAIDS

DiureticsDiureticsRenal PhysiologyRenal Physiology

Nephron processes (pg 378) Nephron processes (pg 378) • ______ ____________ ______• ______ ____________ ______• ______ ____________ ______

Maintain fluid volume, electrolyte Maintain fluid volume, electrolyte concentration, & pH concentration, & pH

Cellular waste Cellular waste 400 ml/d400 ml/d

Glomerular FiltrationGlomerular Filtration

Pressure pushes H2O, electrolytes Pressure pushes H2O, electrolytes other solutes outother solutes out

End product is approx 2L urine/dEnd product is approx 2L urine/d

Tubular ReabsorptionTubular Reabsorption

Most occurs in proximal tubuleMost occurs in proximal tubule• Glucose, amino acids, and approx Glucose, amino acids, and approx 80% of 80% of

H2O, Sodium, Potassium, & ChlorideH2O, Sodium, Potassium, & Chloride Loop of HenleLoop of Henle

• Descending limb H2ODescending limb H2O• Ascending SodiumAscending Sodium

Distal TubuleDistal Tubule• Exchange sodium & potassiumExchange sodium & potassium• H2O H2O

Antidiuretic Hormone (ADH) & Antidiuretic Hormone (ADH) & AldosteroneAldosterone

ADH promotes reabsorption of ____ADH promotes reabsorption of ____ Urine becomes more concentratedUrine becomes more concentrated Aldosterone promotes sodium-Aldosterone promotes sodium-

potassium exchangepotassium exchange Promotes sodium retention and Promotes sodium retention and

potassium losspotassium loss

Tubular SecretionTubular Secretion

Proximal tubuleProximal tubule• Uric acid, Cr, Hydrogen ions, & ammonia Uric acid, Cr, Hydrogen ions, & ammonia

Distal tubuleDistal tubule• Potassium ions, hydrogen ions, & Potassium ions, hydrogen ions, &

ammoniaammonia

Hydrogen balance maintains pHHydrogen balance maintains pH

DiureticsDiuretics

Decrease blood pressure by sodium Decrease blood pressure by sodium & water depletion& water depletion

Initially, BV & CO are decreasedInitially, BV & CO are decreased Eventually, CO normalizes but Eventually, CO normalizes but

vascular resistance is decreasedvascular resistance is decreased May be used alone or in combination May be used alone or in combination

with anti-hypertensiveswith anti-hypertensives

Thiazide DiureticsThiazide Diuretics

Chemically related to sulfonamidesChemically related to sulfonamides Decrease reabsorption of sodium, Decrease reabsorption of sodium,

H2O, Chloride, & bicarb @ distal H2O, Chloride, & bicarb @ distal convoluted tubuleconvoluted tubule

Not a strong diureticNot a strong diuretic Ineffective for immediate diuresisIneffective for immediate diuresis DOC for long term managementDOC for long term management

Thiazide PrototypeThiazide PrototypeHydrochorothiazide (Hydrodiuril)Hydrochorothiazide (Hydrodiuril)

Diuresis in about 2 Diuresis in about 2 hourshours

Promotes excretion Promotes excretion of chloride, of chloride, potassium, potassium, magnesium, & magnesium, & bicarb bicarb

ContraindicationsContraindications

Allergy to ____Allergy to ____ PregnancyPregnancy

Loop DiureticsLoop Diuretics

Inhibit sodium & chloride Inhibit sodium & chloride reabsorption at the ascending limb of reabsorption at the ascending limb of the loop of Henlethe loop of Henle

Significant diuresis, w/i 5 min (IV)Significant diuresis, w/i 5 min (IV) High ceilingHigh ceiling Postdiuretic phase may absorb more Postdiuretic phase may absorb more

sodiumsodium DOC in impaired renal functionDOC in impaired renal function

Loop Diuretic PrototypeLoop Diuretic PrototypeFurosimide (Lasix)Furosimide (Lasix)

Most commonly Most commonly usedused

Do not give if Do not give if discoloreddiscolored

OtotoxicityOtotoxicity

Side EffectSide EffectHypokalemiaHypokalemia

Serum potassium levels (what is Serum potassium levels (what is normal?)normal?)

EKGEKG HypotensionHypotension N&V, anorexiaN&V, anorexia Muscle weakness Muscle weakness ConfusionConfusion

Teaching Teaching DiureticsDiuretics

Avoid excess table saltAvoid excess table salt Periodic serum Periodic serum

potassium levelspotassium levels Increase potassium Increase potassium

rich foodsrich foods Diabetic?Diabetic? PhotosensitivityPhotosensitivity Change positions Change positions

slowlyslowly Take with foodTake with food

Potassium Sparing DiureticsPotassium Sparing Diuretics

Distal tubule to decrease sodium Distal tubule to decrease sodium reabsorption and potassium reabsorption and potassium excretionexcretion

Weak diureticWeak diuretic Usually in combinationUsually in combination

Potassium Sparing DiureticsPotassium Sparing DiureticsPrototype: Spironolactone Prototype: Spironolactone

(Aldactone)(Aldactone) Aldosterone Aldosterone

antagonistantagonist Major side effect Major side effect

hyperkalemiahyperkalemia Do not use with Do not use with

renal insufficiencyrenal insufficiency

TeachingTeaching

No salt substitutesNo salt substitutes No potassium No potassium

supplementssupplements

ContraindicationsContraindications

Renal failureRenal failure

Nursing ImplicationsNursing ImplicationsAll DiureticsAll Diuretics

Give in AMGive in AM I & O, daily weights, BPI & O, daily weights, BP Assess for edemaAssess for edema Monitor for coughingMonitor for coughing Skin turgor Skin turgor HyperglycemiaHyperglycemia HyperuricemiaHyperuricemia Pulmonary edemaPulmonary edema

Potassium SparingPotassium Sparing

HyperkalemiaHyperkalemia• Potassium over ?Potassium over ?• ECG changesECG changes• ArrhythmiasArrhythmias

QuestionsQuestions

The nurse is explaining HTN to a client. The nurse is explaining HTN to a client. Which is the best explanation for why Which is the best explanation for why hypertension develops?hypertension develops?

A)A) ““Americans have a poor diet”Americans have a poor diet”B)B) ““Its is because of your sedentary Its is because of your sedentary

lifestyle”lifestyle”C)C) ““we really don’t understand the reasons we really don’t understand the reasons

behind hypertension”behind hypertension”D)D) ““one or more of the body’s one or more of the body’s

compensatory systems has gone awry”compensatory systems has gone awry”

QuestionsQuestions

A client with an order for Furosimide (Lasix) A client with an order for Furosimide (Lasix) is experiencing hypokalemia.is experiencing hypokalemia.

What should the nurse do?What should the nurse do?

A) Give the Furosimide with a K+ A) Give the Furosimide with a K+ supplementsupplement

B)B) Give Spironolactone (Aldactone) STATGive Spironolactone (Aldactone) STAT

C)C) Hold the FurosimideHold the Furosimide

D)D) Call the labCall the lab